In recent years, integration density has become higher and higher in mounting of power semiconductor modules. Mounting external lead-out terminals of a package on a circuit substrate requires reliability of bonding strengths between the external lead-out terminals such as main terminals and control terminals and the circuit substrate and of bonded portions, and additionally requires positional accuracy relating to locations of the external lead-out terminals.
FIG. 11 is a structural view of a main part of a conventional power semiconductor module 500. A main terminal 53 and a control terminal 54 that are independent terminals are bonded to a circuit substrate 52 securely bonded on a heat-dissipating base 51, by soldering or welding. The circuit substrate 52 is covered with a resin case 55. In the resin case 55, there are formed opening portions 56 and 57, through which tip portions of the main terminal 53 and the control terminal 54 are exposed outwardly from the resin case 55. In addition, the independent terminals are terminals that are not insert-molded in the resin case 55.
In the power semiconductor module shown in FIG. 11, when a compressive load is applied to the control terminal 54, disadvantages occur where the control terminal 54 sinks into the resin case 55 or the circuit substrate 52 is cracked in a case in which the control terminal 54 is welded to the circuit substrate 52 or the control terminal 54 is less deformed. Additionally, application of a tensile load causes a disadvantage where the control terminal 54 is pulled out from the resin base 55.
One technique for solving these troubles is disclosed in Patent Document 1.
FIG. 12 are structural views of a main part of a conventional semiconductor device 600 described in Patent Document 1, in which FIG. 12(a) is a top view; FIG. 12(b) is a side view taken along line XIIb-XIIb of FIG. 12(a); FIG. 12(c) is a front view of a main terminal when seen from an arrow A direction of FIG. 12(a); and FIG. 12(d) is a detailed view of a section B of FIG. 12(b). The semiconductor device is a power semiconductor module such as an IGBT module.
The semiconductor device 600 includes a resin case 60, a heat-dissipating base 61, a circuit substrate 62, a nut glove 65, a main terminal 63, a control terminal 13f, and a resin block 71. The circuit substrate 62 is securely bonded on the heat-dissipating base 61. The main terminal 63 and the control terminal 13f that are independent terminals for external leading-out (external connection) are soldered or welded onto the circuit substrate 62.
The main terminal 63 and the control terminal 13f are exposed outside the resin case 60 from an opening portion 64 and an opening portion 2a, respectively, on a top surface side of the resin case 60. Additionally, the main terminal 63 is secured to the resin case 60 by the nut glove 65, and the control terminal 13f is secured to the resin case 60 by the resin block 71. The nut glove 65 is inserted between two legs 66 of the main terminal 63 so as to pass through an inside of a U-shaped hole of the main terminal 63 exposed from the opening portion 64 on the top surface side of the resin case 60, thereby securing the main terminal 63.
The control terminal 13f includes an upright portion that is substantially upright with respect to the circuit substrate 62 and whose one end is exposed outside the resin case 60 and a connecting portion connected to the other end of the upright portion so as to form a substantially L-shape together with the upright portion. A side end face of the upright portion (hereinafter referred to simply as side end face) of the control terminal 13f is provided with first and second protrusions 16a and 17a and a concave valley 18a formed by the first protrusion portion 16a and the second protrusion portion 17a. 
FIG. 13 are views of the resin block 71 that secures the control terminal 13f, in which FIG. 13(a) is a plan view; FIG. 13(b) is a bottom view; and FIG. 13(c) is a side view. A third protrusion portion 73 is formed on both side faces 72 of the resin block 71, and a fourth protrusion portion 75 is formed on a bottom surface 74 thereof. Additionally, a convex stepped portion 76 is formed on both side faces 72, and a concave groove 79 is formed at a front-side end portion 78 of the resin block 71. Front-side end portions 77 of the convex stepped portions 76 are fitted into the valley 18a between the first protrusion portion 16a and the second protrusion portion 17a of the control terminal 13f. 